The Relationship Between Alcohol Consumption, BMI, and Type 2 Diabetes: A Systematic Review and Dose-Response Meta-analysis

BACKGROUND: Moderate alcohol use may be associated with lower risk of type 2 diabetes mellitus (T2DM). Previous reviews have reached mixed conclusions. PURPOSE: To quantify the dose-response relationship between alcohol consumption and T2DM, accounting for differential effects by sex and BMI.

DATA SOURCES: Medline, Embase, Web of Science, and one secondary data source.

STUDY SELECTION: Cohort studies on the relationship between alcohol use and T2DM.

DATA EXTRACTION: Fifty-five studies, and one secondary data source, were included with a combined sample size of 1,363,355 men and 1,290,628 women, with 89,983 and 57,974 individuals, respectively, diagnosed with T2DM.

DATA SYNTHESIS: Multivariate dose-response meta-analytic random-effect models were used. For women, a J-shaped relationship was found with a maximum risk reduction of 31% (relative risk [RR] 0.69, 95% CI 0.64-0.74) at an intake of 16 g of pure alcohol per day compared with lifetime abstainers. The protective association ceased above 49 g per day (RR 0.82, 95% CI 0.68-0.99). For men, no statistically significant relationship was identified. When results were stratified by BMI, the protective association was only found in overweight and obese women.

LIMITATIONS: Our analysis relied on aggregate data. We included some articles that determined exposure and cases via self-report, and the studies did not account for temporal variations in alcohol use.

CONCLUSIONS: The observed reduced risk seems to be specific to women in general and women with a BMI >/=25 kg/m2. Our findings allow for a more precise prediction of the sex-specific relationship between T2DM and alcohol use, as our results differ from those of previous studies.